In a 12-week study of middle schoolers, the kids who jumped rope the basic, single-bounce way saw their waists grow by almost 8 percent. The kids who did freestyle rope skipping instead didn't. Same rope. Same 12 weeks. Same three sessions a week. Opposite result on the one measurement most people jump rope to fix.
The Study Nobody Cites When They Sell You "Jump Rope Burns Belly Fat"
Researchers at a public middle school in Shanghai split 60 students into three groups for 12 weeks: freestyle rope skipping, traditional single-rope jumping, and a control group that just did free play after school. Three 45-minute sessions a week, every week, for three months. Both jump rope groups trained at the same intensity — roughly 2,460 to 2,640 jumps per 30-minute session, enough to count as moderate-to-vigorous activity. The only difference was style. One group learned footwork, rhythm, and varied tricks set to music. The other group just counted basic bounces and tried to go faster.
Two Groups, Same Rope, Very Different Results
On almost every test, both jump rope groups beat the kids who didn't jump rope at all. Standing long jump improved 5.29 percent in the freestyle group and 2.79 percent in the traditional group, while the control group actually got worse. Grip strength told the same story — both rope groups gained roughly 10 to 13 percent, while the control group's grip strength collapsed by more than a quarter. Flexibility improved in both groups too, though freestyle's gain was dramatically larger. So far, this reads like every other "jump rope works" headline.
The Part That Should Worry You If You're Doing It "The Normal Way"
Then there's waist circumference. The traditional, basic-bounce group's waists got significantly bigger over the 12 weeks — up 7.88 percent, a result the study's own authors flagged as contradicting earlier jump rope research and calling for further investigation. The freestyle group saw no significant change either way. Nobody's waist shrank. But only one style made it worse, and it was the plain, no-frills version most beginner guides teach first: feet together, rope under, bounce, repeat, go faster.
Both intervention groups showed significant improvements in nearly every fitness measure compared to control — except waist circumference, where the traditional jump rope group's increase ran counter to what the researchers expected going in.
Why Freestyle Beat the Basic Jump on Almost Everything Else
The freestyle group also came out ahead on heel bone density, gaining about 7 percent where the other two groups showed no meaningful change. The researchers' read: freestyle rope skipping varies the load, the footwork, and the rhythm constantly, which may do more for bone and body composition than repeating the exact same bounce for 30 minutes. The basic style is simpler to learn, which is probably why it's the default in almost every beginner tutorial. Simpler to learn doesn't mean better for your body.
What This Means for How You Should Actually Train
This was one 12-week study of 60 middle schoolers in one school, measured with ultrasound bone density and a tape measure, not a full-body scan. It's not proof that basic jumping makes anyone's waist bigger forever. But it's a real, published, statistically significant result that cuts directly against the lazy assumption that any jump rope session automatically trims your midsection. The style you jump matters. Variety — in footwork, rhythm, and tempo — isn't just there to look impressive. It appears to be doing real work the repetitive version isn't.
If you've been doing the same basic bounce for months because nobody ever told you there was another way, that's not your fault. Most people never get past the "feet together, go fast" stage because nobody shows them what comes next.
Source: Yang, X., Lee, J., Gu, X., Zhang, X., & Zhang, T. (2020). Physical Fitness Promotion among Adolescents: Effects of a Jump Rope-Based Physical Activity Afterschool Program. Children, 7(8), 95.
The Training App inside every Performance Rope purchase exists for exactly this reason — so you're not stuck doing the same basic bounce for three months because nobody showed you the next move. Get the rope for $20 today, and unlock the full Training App — a program built around you, a workout timer that structures your sessions, and progress tracking that actually tells you if what you're doing is working — for $9.99/month after. A short minimum term applies; details are on the product page.